Voltage regulator and power supply

A power supply, comprising a voltage regulator, wherein the voltage regulator comprises:

• an operational amplifier including an input terminal and an output terminal, and the operational amplifier is configured to generate an output voltage to be output from the output terminal based on a reference voltage received from the input terminal;
• and
• an offset voltage control module including one stage of regulation branch or more stages of regulation branches connected in parallel, and the offset voltage control module is configured to control an offset voltage of the operational amplifier based on selection of the regulation branch to regulate the output voltage,
• wherein the one stage of regulation branch or each of the more stages of regulation branches comprises a regulation element and a regulation switch, and the regulation branch is connected to a device affecting the offset voltage inside the operational amplifier;
• wherein conduction of the regulation branch is controlled by controlling conduction of the regulation switch, such that the regulation element of the conducted regulation branch is connected to the operational amplifier to control the offset voltage of the operational amplifier.

A voltage regulator, comprising:

• an operational amplifier including an input terminal and an output terminal, and the operational amplifier is configured to generate an output voltage to be output from the output terminal based on a reference voltage received from the input terminal;
• and
• an offset voltage control module including one stage of regulation branch or more stages of regulation branches connected in parallel, and the offset voltage control module is configured to control an offset voltage of the operational amplifier based on selection of the regulation branch to regulate the output voltage,
• wherein the operational amplifier comprises a differential input pair transistors;
• wherein at least one of the differential input pair transistors is connected in parallel to any one or more stages of regulation branches in the offset voltage control module to control a voltage difference between the differential input pair transistors by the any one or more stages of regulation branches in the offset voltage control module, and hence to control the offset voltage of the operational amplifier.